spongy brake pedal

Subject: spongy brake pedal Tue Dec 07, 2021 8:35 am

My brake pedal is spongy - why? thx

Can it be the rear drums/pads causing this?

Is there just one cylinder (master cylinder - behind dash) that compresses the brake fluid(together with the brake booster) for both front and rear brakes - ie is there such a thing as a rear wheel cylinder?

Could it be the master cylinder / brake booster - all of teh above?!

simply try to spend the least possible for safe brakes. - rather than change everything. - are there test you can do? i guess look for leaks..

Subject: Re: spongy brake pedal Tue Dec 07, 2021 1:52 pm

i watched some youtube videos now, so got the knowledge.

spongeyness could be master brake cylinder.

A rear brake cylinder is leaking very very slightly - not sure if it would be this - going to replace anyway.

Subject: Re: spongy brake pedal Wed Dec 08, 2021 2:19 am

Yes mate, an engine that doesn't work is a pain but not life threatening, brakes that don't work correctly are a serious issue. I hope you get it all fixed safely and it doesn't cost a fortune.

Subject: Re: spongy brake pedal Wed Dec 08, 2021 12:43 pm

Bagface wrote:: My brake pedal is spongy - why? thx

Can it be the rear drums/pads causing this?

Is there just one cylinder (master cylinder - behind dash) that compresses the brake fluid(together with the brake booster) for both front and rear brakes - ie is there such a thing as a rear wheel cylinder?
Could it be the master cylinder / brake booster - all of teh above?!
simply try to spend the least possible for safe brakes. - rather than change everything. - are there test you can do? i guess look for leaks..

This usually indicates air in the system, or dodgy rubber hoses, or a slight leak.
Replacing the brake fluid would be the first task, and examining all the wheel brakes for leaks and old hoses.

Subject: Re: spongy brake pedal Thu Dec 09, 2021 6:34 am

I’ll second that comment that spongey pedal usually means air in system, the remedy for which is to bleed the brakes. Super easy job.
Faulty master cylinder is usually indicated by a pedal that slowly sinks down while applying standing still.
Faulty booster is tested by turning engine off and pumping the pedal. The first pump should be soft and long travel and it should get firmer and higher with several pumps.

Subject: Re: spongy brake pedal Fri Dec 17, 2021 4:46 am

thank you

rear brake cylinder in ndrum brake slight fluid

going to start with
new drums (very worn!)
new shows (not touching all of surface
and new cylinders

also had a hot front wheel - was just the brake caliper slides stuck - greased up - no longer hot wheel.

i will let everyone know if i end up need a new master cylinder - i hope no $$$$!

ps my second hand fuel pump is still going strong - i regret ever going to see a so called diesel fuel pump specialist for recondition that put it back in likely crossthreaded and exploded it - what a clueless kook! he said the van was rightoff and he was keeping my fuel pump and my spare $400 ecu went missing. I bought a used one asked someone that worked on 4wds to install it - turned up and drove into the sunset with no problem. Beware! He also charged me a lot for a diagnosis saying it was the ECU. Then changed their mind about that when i turned up with my spare - still had to pay..

My pain gripe is that i drive locally a lot in it - lucky to get 320km to tank - open road is ok - 470km.